JP3000705B2 - Positive resist composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist composition, and more particularly to a positive resist composition for fine processing required for manufacturing semiconductor devices, magnetic bubble memory devices, integrated circuits and the like. .

[0002]

2. Description of the Related Art In the manufacture of semiconductors, a photosensitive film is formed by coating a resist on the surface of a silicon wafer, and a latent image is formed by irradiating light, and then developed to form a negative or positive image. 2. Description of the Related Art A semiconductor element is formed by a lithography technique. Conventionally, as a resist composition for forming a semiconductor device, a negative resist comprising a cyclized polyisoprene and a bisdiazide compound has been known. However, since this negative resist is developed with an organic solvent, the swelling is large and the resolution is limited,
It has a disadvantage that it cannot cope with the manufacture of a highly integrated semiconductor.
On the other hand, it is considered that the positive resist composition is superior in resolution to the negative resist composition and can sufficiently cope with high integration of semiconductors. Currently, a positive resist composition generally used in this field comprises a novolak resin and a quinonediazide compound. However, conventional positive resist compositions have not always obtained satisfactory results in various properties such as sensitivity, residual film ratio, resolution, heat resistance, and storage stability, and are required to improve performance.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a positive resist composition having excellent characteristics such as sensitivity, residual film ratio, resolution, heat resistance and storage stability, and particularly suitable for fine processing of 1 μm or less. To provide things. The present inventors have conducted intensive studies to overcome the problems of the prior art, and as a result, in a positive resist composition containing an alkali-soluble phenol resin and a photosensitizer, a positive resist composition having a phenolic hydroxyl group as the photosensitizer. By using an ester of a compound of the formula and a quinonediazidesulfonic acid compound,
The present inventors have found that the above object can be achieved, and have completed the present invention based on the knowledge.

[0004]

Means for Solving the Problems Thus, according to the present invention, in a positive resist composition containing an alkali-soluble phenolic resin and a photosensitive agent, as the photosensitive material, the following general formula [I]

[0005]

Embedded image (R ₁ -R ₆ : hydrogen, halogen, hydroxyl group, C ₁ -C ₄ alkyl group, C ₂ -C ₅ alkenyl group, or C ₁ -C ₈ alkoxy group, which may be the same or different . R _7: an alkyl group of C ₁ ~C ₈ R _8:. hydrogen, an aryl group of C ₁ -C ₄ alkyl group, an alkenyl group of C ₂ -C ₅ or C ₆ -C _15,. Table in)
At least one for each of the three benzene rings
And has at least one benzene ring
Phenolic compound having at least one alkoxy group
Product (I) and general formula [II]

[0006]

Embedded image (R ₉ -R ₁₀ : hydrogen, halogen, hydroxyl, C ₁ -C ₄ alkyl, C ₂ -C ₅ alkenyl, C ₁ -C ₈ alkoxy, or acyl, the same or different R _{11 to} R ₁₂ : hydrogen, halogen, a C ₁ -C ₄ alkyl group,
Alkenyl C ₂ -C ₅ or an alkoxy group of C ₁ ~C _8,, may be the same or different. R _13: an alkyl group of C ₁ -C _8. R _{14 is} hydrogen, a C ₁ -C ₄ alkyl group, a C ₂ -C ₅ alkenyl group, or a C ₆ -C ₁₅ aryl group. A) a phenolic compound (II) having at least two hydroxyl groups on each of two benzene rings and having at least one alkoxy group on one benzene ring having no hydroxyl group; At least one selected from the group
The esterification rate of the phenolic compounds of
% Of a quinonediazide sulfonic acid ester. Hereinafter, the present invention will be described in detail.

(Alkali-Soluble Phenol Resin) Examples of the alkali-soluble phenol resin used in the present invention include a condensation reaction product of a phenol and an aldehyde, a condensation reaction product of a phenol and a ketone, and a vinylphenol-based resin. Examples include polymers, isopropenylphenol-based polymers, and hydrogenation products of these phenolic resins.

Specific examples of the phenols used herein include monovalent phenols such as phenol, cresol, xylenol, ethyl phenol, propyl phenol, butyl phenol, and phenyl phenol, resorcinol, pyrocatechol, hydroquinone, bisphenol A, and phenol. Examples include polyhydric phenols such as loglucinol and pyrogallol. Specific examples of aldehydes include formaldehyde, acetaldehyde, benzaldehyde, terephthalaldehyde, and the like. Specific examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, and the like. These condensation reactions can be performed according to a conventional method.

The vinylphenol-based polymer is selected from a homopolymer of vinylphenol and a copolymer of vinylphenol with a component copolymerizable with vinylphenol. Specific examples of the copolymerizable component include acrylic acid, methacrylic acid and derivatives thereof, styrene, maleic anhydride, maleic imide derivative, vinyl acetate, acrylonitrile, and the like.

The isopropenylphenol-based polymer is selected from a homopolymer of isopropenylphenol and a copolymer of isopropenylphenol with a copolymerizable component. Specific examples of the copolymerizable component include acrylic acid, methacrylic acid and derivatives thereof, styrene, maleic anhydride, a maleimide derivative, vinyl acetate, acrylonitrile, and the like.

When a hydrogenation reaction product of a phenol resin is used, the product can be produced by any known method. For example, it can be achieved by dissolving a phenol resin in an organic solvent and introducing hydrogen in the presence of a homogeneous or heterogeneous hydrogenation catalyst. These alkali-soluble phenol resins may be used alone or in combination of two or more.

The positive resist composition of the present invention may contain, for example, a copolymer of styrene with acrylic acid, methacrylic acid or maleic anhydride in order to improve developability, storage stability, heat resistance and the like. Polymers, copolymers of alkenes and maleic anhydride, vinyl alcohol polymers, vinylpyrrolidone polymers, rosin, shellac and the like can be added. The addition amount is from 0 to 50 parts by weight, preferably from 5 to 20 parts by weight, based on 100 parts by weight of the alkali-soluble phenol resin.

(Photosensitizer) The photosensitizer used in the present invention is not particularly limited as long as it is a quinonediazidosulfonic acid ester of the compound represented by the general formula [I] or [II]. 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-
Naphthoquinonediazide-5-sulfonic acid ester, 2,
1-naphthoquinonediazide-4-sulfonic acid ester,
Examples thereof include 2,1-naphthoquinonediazide-5-sulfonic acid ester and other quinonediazidesulfonic acid esters.

The phenolic compound represented by the general formula [I] or [II] serving as a nucleus of the photosensitive agent used in the present invention is characterized by having an alkoxy group together with a phenolic hydroxyl group. It can be obtained by condensing a substituted phenol and a benzaldehyde having an alkoxy group with an acidic catalyst, or alkylating a part of the hydroxyl group of the corresponding phenol with an alkyl sulfate in the presence of a base. Formula (I) or (I
Specific examples of the phenol compound represented by I] include the following.

[0015]

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[0016]

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[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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[0022]

[12]

[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

The photosensitive agent used in the present invention is an ester of a phenol compound represented by the general formula [I] or [II] and a quinonediazidesulfonic acid compound. Examples of the quinonediazidesulfonic acid compound include 1,2-benzoquinonediazide-4-sulfonic acid, 1,2-naphthoquinonediazide-4-sulfonic acid, 1,2-naphthoquinonediazide-5-sulfonic acid, and 2,1-naphtho. O-Quinonediazidesulfonic acid compounds such as quinonediazide-4-sulfonic acid and 2,1-naphthoquinonediazide-5-sulfonic acid; and other quinonediazidesulfonic acid derivatives. The quinonediazidesulfonic acid ester used in the present invention is prepared by converting a quinonediazidesulfonic acid compound into sulfonyl chloride with chlorosulfonic acid according to a conventional method, and obtaining the obtained quinonediazidosulfonyl chloride with a phenol compound represented by the general formula (I) or (II). By condensation. For example, a phenol compound represented by the general formula [I] or [II] and a predetermined amount of 1,2-naphthoquinonediazide-5-sulfonyl chloride are dissolved in a solvent such as dioxane, acetone or tetrahydrofuran, and triethylamine, pyridine, sodium carbonate is dissolved. The reaction product can be prepared by adding a basic catalyst such as sodium hydrogencarbonate, sodium hydroxide or potassium hydroxide, and washing the resulting product with water and drying.

In the photosensitizer used in the present invention, the ratio of esterification of the quinonediazidesulfonic acid compound to the phenol compound represented by the general formula [I] or [II] is 67 to 100 mol%, preferably 67 to 9 mol%.
The range is 5 mol%. If the ratio of esterification is too low, pattern shape and resolution may be deteriorated. If the ratio of esterification is too high, sensitivity may be deteriorated.

The mixing ratio of the photosensitive agent used in the present invention is not particularly limited, but is usually 1 to 100 parts by weight based on 100 parts by weight of the alkali-soluble phenol resin.
Preferably it is in the range of 5 to 40 parts by weight. If the compounding ratio is too small, a sufficient residual film ratio cannot be obtained, leading to deterioration in resolution. Conversely, if the compounding ratio is too large, heat resistance deteriorates, which is not preferable.

The photosensitive agents used in the present invention can be used alone or in combination of two or more. Further, it can be used in combination with another type of photosensitive agent. The other type of photosensitive agent to be mixed is not particularly limited, and any known quinonediazidesulfonic acid ester can be used. Specific examples include cresol, xylenol, resorcin, cacol, hydroquinone, pyrogallol, phloroglucinol, phloroglucid, 2,3,4-trihydroxybenzophenone, 2,
4,4-trihydroxybenzophenone, 2,3,4
4'-tetrahydroxybenzophenone, 2,2 ',
4,4'-tetrahydroxybenzophenone, 2,
2 ', 3,4,4'-pentahydroxybenzophenone, 2,2', 3,4,5'-pentahydroxybenzophenone, 2,3,3 ', 4,5'-pentahydroxybenzophenone, 2,3 3 ', 4,4', 5'-hexahydroxybenzophenone, 2,3 ', 4,4',
5 ', 6-hexahydroxybenzophenone, methyl gallate, ethyl gallate, propyl gallate, 2,2-
Bis (4-hydroxyphenyl) propane, 2,2-bis (2,4-dihydroxyphenyl) propane, 2,2
-Bis (2,3,4-trihydroxyphenyl) propane, cresol novolak resin, resorcin-acetone resin, pyrogallol-acetone resin, polyvinylphenol resin and quinonediazidesulfonic acid ester such as copolymer of vinylphenol.

(Other components) The positive resist composition of the present invention is usually used by dissolving it in a solvent in order to form a resist film by coating it on a substrate. As the solvent, ketones such as acetone, methyl ethyl ketone, cyclohexanone and cyclopentanone; n-propyl alcohol,
iso-propyl alcohol, n-butyl alcohol,
Alcohols such as cyclohexanol; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether and dioxane; alcohol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; propyl formate, butyl formate, propyl acetate, butyl acetate; Esters such as methyl propionate, ethyl propionate, methyl acetate, ethyl acetate, methyl lactate and ethyl lactate; cellosolve esters such as cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate and butyl cellosolve acetate; propylene glycol; Propylene glycol monomethyl ether, prolene glycol monomethyl ether acetate Propylene glycols such as propylene glycol monoethyl ether acetate and propylene glycol monobutyl ether; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol methyl ethyl ether; halogenated hydrocarbons such as trichloroethylene , Aromatic hydrocarbons such as toluene and xylene;
Examples thereof include polar solvents such as dimethylacetamide, dimethylformamide, and N-methylacetamide. These may be used alone or in combination of two or more. If necessary, the positive resist composition of the present invention may contain compatible additives such as dyes, surfactants, storage stabilizers, sensitizers, striation inhibitors, and plasticizers. it can.

As the developer for the positive resist composition of the present invention, an aqueous alkali solution is used. Specifically, sodium hydroxide, potassium hydroxide, sodium silicate,
Inorganic amines such as ammonia; primary amines such as ethylamine and propylamine; second amines such as diethylamine and dipropylamine; tertiary amines such as trimethylamine and triethylamine; dimethylmethanolamine and triethanolamine Alcohol amines; tetramethylammonium hydroxide,
Examples include quaternary ammonium salts such as tetraethylammonium hydroxide, trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, and trimethylhydroxyethylammonium hydroxide. Further, if necessary, methanol, ethanol,
An appropriate amount of a water-soluble organic solvent such as propanol or ethylene glycol, a surfactant, a storage stabilizer, or a dissolution inhibitor for a resin can be added.

[0045]

The present invention will be described more specifically below with reference to examples and comparative examples. In the examples, parts and%
Are by weight unless otherwise specified.

(Synthesis Example 1) 20.7 g of phenol (0.
22 mol) and 15.2 g (0.10 mol) of vanillin
Was placed in a flask, and 31.1 g of glacial acetic acid was added to dissolve it. 16.4 g of sulfuric acid / acetic acid (a mixed acid having a weight ratio of 1.1 / 1.0) was added thereto, and reacted at room temperature for 48 hours with stirring. After washing the reaction solution with 300 g of water, the precipitate was separated by filtration and dissolved in 200 g of ethyl ether. This was washed three times with 200 g of water and concentrated to obtain a solid content. The solid content is recrystallized with ethyl acetate and the crystals are filtered,
After drying, 26.8 g of the compound of the structural formula [Formula 5] was obtained.

The compound of the formula (5) and the
ol%, 1,2-naphthoquinonediazide-5
Sulfonyl chloride was dissolved in dioxane to make a 10% solution. While controlling this solution at 20 to 25 ° C., triethylamine was added to 30 equivalents of 1.2 equivalents of 1,2-naphthoquinonediazide-5-sulfonyl chloride.
The reaction was completed by dropping over a period of 4 minutes and holding for 4 hours. The precipitated salt was separated by filtration and poured into ion-exchanged water 10 times the amount of the reaction solution. The precipitated solid was filtered, washed with water, and dried to obtain a photosensitive agent A as an esterification reaction product.

(Synthesis Example 2)
The compound of the structural formula [Formula 7] was obtained in the same manner as in Synthesis Example 1 using 2,5-xylenol and vanillin. Further, the same esterification reaction as in Synthesis Example 1 was performed to obtain a photosensitive agent B.

(Synthesis Example 3) As a raw material of a photosensitive agent core, o
Using -cresol and o-vanillin, a compound of the above structural formula [Formula 9] was obtained in the same manner as in Synthesis Example 1. Further, the same esterification reaction as in Synthesis Example 1 was carried out, and photosensitive agent C was used.
I got

(Synthesis Example 4) Using homocatechol and vanillin as raw materials for a photosensitizer nucleus, a compound of the above-mentioned structural formula [Formula 16] was obtained in the same manner as in Synthesis Example 1. Further, from the compound [Chemical Formula 16] and 1,2-naphthoquinonediazide-5-sulfonyl chloride corresponding to 75 mol% of the hydroxyl group, the same esterification reaction as in Synthesis Example 1 was carried out to obtain a photosensitive agent D.

(Synthesis Example 5) A compound of the above structural formula [Formula 19] was obtained in the same manner as in Synthesis Example 1 using homocatechol and o-anisaldehyde as raw materials for a photosensitizer nucleus. Further, the compound [Formula 19] and 80 m
ol%, 1,2-naphthoquinonediazide-5
The same esterification reaction as in Synthesis Example 1 was performed from sulfonyl chloride to obtain a photosensitizer E.

(Synthesis Example 6) From the compound of the above formula [Formula 7] and 1,2-naphthoquinone azido-5-sulfonyl chloride having 85 mol% of the hydroxyl groups, an esterification reaction similar to that of Synthesis Example 1 was carried out to obtain a photosensitive compound. Agent F was obtained.

(Synthesis Example 7) The same esterification reaction as in Synthesis Example 1 was carried out from 2,3,4-trihydroxybenzophenone and 1,2-naphthoquinonediazido-5-sulfonyl chloride corresponding to 67 mol% of the hydroxyl groups. This gave a photosensitive agent G.

[Example 1] Novolak resin 10 obtained by adding formalin to a mixture of m-cresol / p-cresol (5/5) and condensing in a conventional manner using an oxalic acid catalyst.
0 parts and 25 parts of photosensitive agent A were dissolved in 350 parts of ethyl lactate, and filtered through a 0.1 μm Teflon filter (polytetrafluoroethylene filter) to prepare a resist solution. The resist solution was applied on a silicon wafer by a coater, and prebaked at 100 ° C. for 90 seconds to form a resist film having a thickness of 1.17 μm. This wafer was exposed using a g-line stepper NSR1505G6E (manufactured by Nikon Corporation, NA = 0.54) and a test reticle. Next, a positive pattern was formed by developing with a 2.38% aqueous solution of tetramethylammonium hydroxide by a paddle method at 23 ° C. for 1 minute. The wafer was taken out and observed with an electron microscope to evaluate the resist. Table 1 shows the results. In Table 1, the sensitivity is 1: 1 at 0.65 μm.
The exposure time indicates that the line & space pattern can be formed as designed, and the resolution and pattern shape indicate the critical resolution and the resist shape under these exposure conditions.

Examples 2 to 5 Photosensitive agents B, C,
A resist solution was prepared and evaluated in the same manner as in Example 1 except that D and E were used. Table 1 shows the results.

Comparative Example 1 A resist solution was prepared and evaluated in the same manner as in Example 1 except that photosensitive agent G was used. Table 1 shows the results.

Example 6 A resist solution was prepared in the same manner as in Example 1 except that the photosensitive agent F was used. A resist film was formed and exposed in the same manner as in Example 1 except that the pre-bake was performed at 90 ° C. for 90 seconds. Then, a post-exposure bake (Post Expo) was performed at 110 ° C. for 60 seconds.
Sure Banking) and a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C.,
The pattern was developed by a paddle method for a minute to form a positive pattern. Table 1 shows the evaluation results.

Example 7 Using the resist of Example 6,
Pattern formation and resist evaluation were performed in the same manner as in Example 6, except that exposure was performed using an i-line stepper NSR1505i7A (manufactured by Nikon Corporation, NA = 0.45). The sensitivity was 320 msec. At this time, a 0.45 μm line & space pattern could be resolved, and this pattern had a vertical and good shape. The exposure amount is 340 msec.
Was used to resolve a 0.40 μm line & space pattern.

[0059]

[Table 1]

[0060]

According to the present invention, it is possible to provide a positive resist composition excellent in various properties such as sensitivity, residual film ratio, resolution and heat resistance. The positive resist composition of the present invention is particularly suitable for fine processing of 1 μm or less.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Urushima 1-2-1, Yaiko, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Zeon Co., Ltd. R & D Center (72) Inventor Kazuko Koito, Yakko Kawasaki-ku, Kawasaki-ku, Kanagawa 1-2-1, Japan Zeon Co., Ltd. Research and Development Center (72) Inventor Kakuei Ozawa 1-1-2, Yakko, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Japan Zeon Co., Ltd. Research and Development Center (56) References Special Kaihei 4-284454 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (1)

(57) [Claims] In a positive resist composition containing an alkali-soluble phenol resin and a photosensitizer, the photosensitizer is represented by the following general formula [I]: (R ₁ -R ₆ : hydrogen, halogen, hydroxyl group, C ₁ -C ₄ alkyl group, C ₂ -C ₅ alkenyl group, or C ₁ -C ₈ alkoxy group, which may be the same or different . R _7: an alkyl group of C ₁ ~C ₈ R _8:. hydrogen, an aryl group of C ₁ -C ₄ alkyl group, an alkenyl group of C ₂ -C ₅ or C ₆ -C _15,. A) a phenolic compound (I) having at least one hydroxyl group on each of three benzene rings and having at least one alkoxy group on at least one benzene ring, and a general formula [ II] (R ₉ -R ₁₀ : hydrogen, halogen, hydroxyl, C ₁ -C ₄ alkyl, C ₂ -C ₅ alkenyl, C ₁ -C ₈ alkoxy, or acyl, the same or different R _{11 to} R ₁₂ : hydrogen, halogen, a C ₁ -C ₄ alkyl group,
Alkenyl C ₂ -C ₅ or an alkoxy group of C ₁ ~C _8,, may be the same or different. R _13: an alkyl group of C ₁ -C _8. R _{14 is} hydrogen, a C ₁ -C ₄ alkyl group, a C ₂ -C ₅ alkenyl group, or a C ₆ -C ₁₅ aryl group. A) a phenolic compound (II) having at least two hydroxyl groups on each of two benzene rings and having at least one alkoxy group on one benzene ring having no hydroxyl group; At least one selected from the group
The esterification rate of the phenolic compounds of
% Of quinonediazide sulfonic acid ester.